Commit 35bb4399 authored by Steven Rostedt's avatar Steven Rostedt Committed by Steven Rostedt
Browse files

tracing: Move event storage for array from macro to standalone function 

The code that shows array fields for events is defined for all events.
This can add up quite a bit when you have over 500 events.

By making helper functions in the core kernel to do the work
instead, we can shrink the size of the kernel down a bit.

With a kernel configured with 502 events, the change in size was:

   text    data     bss     dec     hex filename
12990946        1913568 9785344 24689858        178bcc2 /tmp/vmlinux
12987390        1913504 9785344 24686238        178ae9e /tmp/vmlinux.patched

That's a total of 3556 bytes, which comes down to 7 bytes per event.
Although it's not much, this code is just called at initialization of
the events.

Link: http://lkml.kernel.org/r/20120810034708.084036335@goodmis.org



Signed-off-by: default avatarSteven Rostedt <rostedt@goodmis.org>
parent 1d6bae96

include/linux/ftrace_event.h

+4 −4
Original line number Diff line number Diff line
@@ -202,6 +202,10 @@ extern int ftrace_event_reg(struct ftrace_event_call *event, 
int ftrace_output_event(struct trace_iterator *iter, struct ftrace_event_call *event,

			char *fmt, ...);



int ftrace_event_define_field(struct ftrace_event_call *call,

			      char *type, int len, char *item, int offset,

			      int field_size, int sign, int filter);



enum {

	TRACE_EVENT_FL_FILTERED_BIT,

	TRACE_EVENT_FL_CAP_ANY_BIT,
@@ -500,10 +504,6 @@ enum { 
	FILTER_TRACE_FN,

};



#define EVENT_STORAGE_SIZE 128

extern struct mutex event_storage_mutex;

extern char event_storage[EVENT_STORAGE_SIZE];



extern int trace_event_raw_init(struct ftrace_event_call *call);

extern int trace_define_field(struct ftrace_event_call *call, const char *type,

			      const char *name, int offset, int size,

include/trace/ftrace.h

+4 −8
Original line number Diff line number Diff line
@@ -302,15 +302,11 @@ static struct trace_event_functions ftrace_event_type_funcs_##call = { \ 
#undef __array

#define __array(type, item, len)					\

	do {								\

		mutex_lock(&event_storage_mutex);			\

		BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);			\

		snprintf(event_storage, sizeof(event_storage),		\

			 "%s[%d]", #type, len);				\

		ret = trace_define_field(event_call, event_storage, #item, \

				 offsetof(typeof(field), item),		\

		ret = ftrace_event_define_field(event_call, #type, len,	\

				#item, offsetof(typeof(field), item),   \

				sizeof(field.item),			\

			 	is_signed_type(type), FILTER_OTHER); \

		mutex_unlock(&event_storage_mutex);			\

		if (ret)						\

			return ret;					\

	} while (0);

kernel/trace/trace_events.c

+0 −6
Original line number Diff line number Diff line
@@ -27,12 +27,6 @@ 


DEFINE_MUTEX(event_mutex);



DEFINE_MUTEX(event_storage_mutex);

EXPORT_SYMBOL_GPL(event_storage_mutex);



char event_storage[EVENT_STORAGE_SIZE];

EXPORT_SYMBOL_GPL(event_storage);



LIST_HEAD(ftrace_events);

static LIST_HEAD(ftrace_common_fields);

kernel/trace/trace_export.c

+4 −8
Original line number Diff line number Diff line
@@ -96,14 +96,10 @@ static void __always_unused ____ftrace_check_##name(void) \ 
#define __array(type, item, len)					\

	do {								\

		BUILD_BUG_ON(len > MAX_FILTER_STR_VAL);			\

		mutex_lock(&event_storage_mutex);			\

		snprintf(event_storage, sizeof(event_storage),		\

			 "%s[%d]", #type, len);				\

		ret = trace_define_field(event_call, event_storage, #item, \

				 offsetof(typeof(field), item),		\

		ret = ftrace_event_define_field(event_call, #type, len,	\

				#item, offsetof(typeof(field), item),   \

				sizeof(field.item),			\

			 	is_signed_type(type), filter_type);	\

		mutex_unlock(&event_storage_mutex);			\

		if (ret)						\

			return ret;					\

	} while (0);

kernel/trace/trace_output.c

+21 −0
Original line number Diff line number Diff line
@@ -20,6 +20,10 @@ static struct hlist_head event_hash[EVENT_HASHSIZE] __read_mostly; 


static int next_event_type = __TRACE_LAST_TYPE + 1;



#define EVENT_STORAGE_SIZE 128

static DEFINE_MUTEX(event_storage_mutex);

static char event_storage[EVENT_STORAGE_SIZE];



int trace_print_seq(struct seq_file *m, struct trace_seq *s)

{

	int len = s->len >= PAGE_SIZE ? PAGE_SIZE - 1 : s->len;
@@ -470,6 +474,23 @@ int ftrace_output_call(struct trace_iterator *iter, char *name, char *fmt, ...) 
}

EXPORT_SYMBOL_GPL(ftrace_output_call);



int ftrace_event_define_field(struct ftrace_event_call *call,

			      char *type, int len, char *item, int offset,

			      int field_size, int sign, int filter)

{

	int ret;



	mutex_lock(&event_storage_mutex);

	snprintf(event_storage, sizeof(event_storage),

		 "%s[%d]", type, len);

	ret = trace_define_field(call, event_storage, item, offset,

				 field_size, sign, filter);

	mutex_unlock(&event_storage_mutex);



	return ret;

}

EXPORT_SYMBOL_GPL(ftrace_event_define_field);



#ifdef CONFIG_KRETPROBES

static inline const char *kretprobed(const char *name)

{

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